ATI: Chapter 31 Angina and Myocardial Infarction

5. A nurse is presenting a community education program on recommended lifestyle changes to prevent angina and myocardial infarction. Which of the following changes should the nurse recommend be made first? A. Diet modification B. Relaxation exercises C. Smoking cessation D. Taking omega‑3 capsules

C. CORRECT: According to the airway, breathing, and circulation (ABC) priority‑setting framework, the first change the nurse should recommend the clients take is to stop smoking. Nicotine causes vasoconstriction, elevates blood pressure, and narrows coronary arteries.

COMPLICATIONS: Acute MI

A complication of angina not relieved by rest or nitroglycerin NURSING ACTIONS ● Administer oxygen. ● Notify the provider immediately.

Stress test

Also known as exercise electrocardiography. Client tolerance of activity is tested using a treadmill, bicycle, or medication to evaluate response to increased heart rate.

MEDICATIONS: Glycoprotein IIB/IIIA inhibitors

Eptifibatide is used to prevent binding of fibrinogen to platelets, in turn blocking platelet aggregation. In combination with aspirin therapy, IIB/IIA inhibitors are standard therapy. NURSING CONSIDERATIONS ● This medication can cause active bleeding. ● Monitor platelet levels. CLIENT EDUCATION: Instruct the client to report evidence of bleeding during medication therapy

COMPLICATIONS: Ischemic mitral regurgitation

Evidenced by development of a new cardiac murmur. NURSING ACTIONS ● Administer oxygen. ● Notify the provider immediately.

MEDICATIONS: Analgesics

Morphine sulfate is an opioid analgesic used to treat moderate to severe pain. Analgesics act on the mu and kappa receptors that help alleviate pain. Activation of these receptors produces analgesia (pain relief), respiratory depression, euphoria, sedation, and decreases in myocardial oxygen consumption and gastrointestinal (GI) motility. !!! Use cautiously with clients who have asthma or emphysema due to the risk of respiratory depression. NURSING CONSIDERATIONS ● For the client having chest pain, assess pain every 5 to 15 min. ● Watch for manifestations of respiratory depression, especially in older adults. If respirations are 12/min or less, stop medication, and notify the provider immediately. ● Monitor vital signs for hypotension and decreased respirations. ● Assess for nausea and vomiting. CLIENT EDUCATION ● If nausea and vomiting persist, advise the client to notify a nurse. ● Teach the client to use the PCA pump, if applicable. The client is the only person who should push the medication administration button. Reassure the client that the safety lockout mechanism on the PCA pump prevents overdosing of the medication.

COMPLICATIONS: Ventricular aneurysms/rupture

Can be due to necrosis from MI. Can present as sudden chest pain, dysrhythmias, and severe hypotension NURSING ACTIONS ● Administer oxygen. ● Notify the provider immediately.

LABORATORY TESTS

Cardiac enzymes released with cardiac muscle injury: ● Myoglobin: Earliest marker of injury to cardiac or skeletal muscle. Levels no longer evident after 24 hr. ● Creatine kinase‑MB: Peaks around 24 hr after onset of chest pain. Levels no longer evident after 3 days. ● Troponin I or T: Any positive value indicates damage to cardiac tissue and should be reported. - Troponin I: Levels no longer evident after 7 to 10 days. - Troponin T: Levels no longer evident after 10 to 14 days.

4. A nurse is teaching a client who has angina about a new prescription for metoprolol. Which of the following statements by the client indicates understanding of the teaching? A. "I should place the tablet under my tongue." B. "I should have my clotting time checked weekly." C. "I will report any ringing in my ears." D. "I will call my doctor if my pulse rate is less than 60.

D. CORRECT: The client is advised to notify the provider if bradycardia (pulse rate less than 60) occurs.

MEDICATIONS: Anticoagulants

Heparin and enoxaparin are used to prevent clots from becoming larger or other clots from forming. NURSING CONSIDERATIONS ● Assess for contraindications (active bleeding, peptic ulcer disease, history of stroke, recent trauma). ● Monitor platelet levels and bleeding times: PT, aPTT, INR, and CBC. ● Monitor for adverse effects of anticoagulants (thrombocytopenia, anemia, hemorrhage). CLIENT EDUCATION: Remind the client of the risk for bruising and bleeding while on this medication.

COMPLICATIONS: Heart failure/cardiogenic shock

Injury to the left ventricle can lead to decreased cardiac output and heart failure. Progressive heart failure can lead to cardiogenic shock. ● This is a serious complication of pump failure, commonly following an MI of 40% blockage. ● Manifestations include tachycardia; hypotension; inadequate urinary output; altered level of consciousness; respiratory distress (crackles and tachypnea); cool, clammy skin; decreased peripheral pulses; and chest pain. NURSING ACTIONS ● Administer oxygen. Intubation and ventilation can be required. ● Administer IV morphine, diuretics, and/or nitroglycerin to decrease preload. Administer IV vasopressors and/ or positive inotropes to increase cardiac output and maintain organ perfusion. ● Maintain continuous hemodynamic monitoring

MI CLASSIFICATION

MIs are classified based on: ● Affected area of the heart: anterior, lateral, inferior, or posterior ● ECG changes produced: ST elevation myocardial infarction vs. non‑ST elevation myocardial infarction ● The time frame within the progression of the infarction: acute, evolving, old

MEDICATIONS: Vasodilators

Nitroglycerin prevents coronary artery vasospasm and reduces preload and afterload, decreasing myocardial oxygen demand. NURSING CONSIDERATIONS ● Used to treat angina and help control blood pressure. ● Used cautiously with other antihypertensive medications. ● Can cause orthostatic hypotension. CLIENT EDUCATION FOR CHEST PAIN ● Instruct the client to stop activity and rest. ● Instruct the client to place a nitroglycerin tablet under the tongue to dissolve (quick absorption). ● If pain is unrelieved in 5 min, the client should call 911 or be driven to an emergency department. ● The client can take up to two more doses of nitroglycerin at 5‑min intervals. ● Remind the client that a headache is a common side effect of this medication. ● Encourage the client to sit and lie down slowly

Electrocardiogram (ECG)

Recording of electrical activity of the heart over time NURSING ACTIONS ● Assess for changes on serial ECGs. ● Angina: ST depression and/or T‑wave inversion indicates presence of ischemia. ● MI: T‑wave inversion indicates ischemia; ST‑segment elevation indicates injury; abnormal Q‑wave indicates necrosis.

Types of angina: Stable

Stable (exertional) angina occurs with exercise or emotional stress and is relieved by rest or nitroglycerin.

Angina and Myocardial Infarction

The continuum from angina to myocardial infarction (MI) is acute coronary syndrome. Symptoms of acute coronary syndrome are due to an imbalance between myocardial oxygen supply and demand. Angina pectoris is a warning sign of an impending acute MI. Women and older adults do not always experience manifestations typically associated with angina or MI. The area of infarction in clients experiencing a myocardial infarction (MI) develops over minutes to hours. Early recognition and treatment of an acute MI is essential to prevent death. Research shows improved outcomes following an MI in clients treated with aspirin, beta‑blockers, and angiotensin‑converting enzyme inhibitors or angiotensin receptor blockers. When blood flow to the heart is compromised, ischemia causes chest pain. Anginal pain is often described as a tight squeezing, heavy pressure, or constricting feeling in the chest. The pain can radiate to the jaw, neck, or arm. Pain unrelieved by rest or nitroglycerin and lasting for more than 15 min differentiates an MI from angina. An abrupt interruption of oxygen to the heart muscle produces myocardial ischemia. Ischemia can lead to tissue necrosis (infarction) if blood supply and oxygen are not restored. Ischemia is reversible. An infarction results in permanent damage. When the cardiac muscle suffers ischemic injury, cardiac enzymes are released into the bloodstream, providing specific markers of MI

Types of angina: Unstable

Unstable (preinfarction) angina occurs with exercise or at rest, but increases in occurrence, severity, and duration over time.

Types of angina: Variant

Variant (Prinzmetal's) angina is due to a coronary artery spasm, often occurring during periods of rest.

ANGINA RISK FACTORS

● Male gender or postmenopausal women ● Ethnic background ● Sedentary lifestyle ● Hypertension ● Tobacco use ● Hyperlipidemia ● Obesity ● Excessive alcohol consumption ● Metabolic disorders (diabetes mellitus, hyperthyroidism) ● Methamphetamine or cocaine use ● Stress (with ineffective coping skills) ● An increased risk of coronary artery disease exists for older adult clients who are physically inactive, have one or more chronic diseases (hypertension, heart failure, and diabetes mellitus), or have lifestyle habits (smoking and diet) that contribute to atherosclerosis. Atherosclerotic changes related to aging predispose the heart to poor blood perfusion and oxygen delivery. ● Incidence of cardiac disease increases with age, especially in the presence of hypertension, diabetes mellitus, hypercholesterolemia, elevated homocysteine, and highly sensitive C‑reactive protein (HS‑CRP).

MEDICATIONS: Beta‑blockers

● Metoprolol has antidysrhythmic and antihypertensive properties that decrease the imbalance between myocardial oxygen supply and demand by reducing afterload and slowing heart rate. ● In an acute MI, beta‑blockers decrease infarct size and improve short‑ and long‑term survival rates. NURSING CONSIDERATIONS ● Beta‑blockers can cause bradycardia and hypotension. Hold the medication if the apical pulse rate is less than 60/min, and notify the provider. ● Avoid giving to clients who have asthma. Cardioselective beta blockers (which affect only beta1 receptors), such as metoprolol, are preferred because they minimize the effects on the respiratory system. ● Use with caution in clients who have heart failure. ● Monitor for decreased level of consciousness, crackles in he lungs, and chest discomfort. CLIENT EDUCATION ● Encourage the client to sit and lie down slowly. ● Remind the client to notify the provider immediately of shortness of breath, edema, weight gain, or cough

NURSING CARE

● Monitor the following. - Vital signs every 5 min until stable, then every hour - Serial ECG, continuous cardiac monitoring - Location, precipitating factors, severity, quality, and duration of pain - Hourly urine output: greater than 30 mL/hr indicates renal perfusion - Laboratory data: cardiac enzymes, electrolytes, ABGs ● Administer oxygen: 2 to 4 L/min. ● Obtain and maintain IV access. ● Promote energy conservation. Cluster nursing interventions.

INTERPROFESSIONAL CARE

● Pain management services can be consulted if pain persists or is uncontrolled. ● Cardiac rehabilitation care can be consulted if the client has prolonged weakness and needs assistance with increasing level of activity. ● Nutritional services can be consulted for diet modification to promote food choices low in sodium and saturated fat. THERAPEUTIC PROCEDURES ● Percutaneous transluminal coronary angioplasty (PTCA) ● Bypass graft (also known as CABG)

1. A nurse is admitting a client who has a suspected myocardial infarction (MI) and a history of angina. Which of the following findings will help the nurse distinguish angina from an MI? A. Angina can be relieved with rest and nitroglycerin. B. The pain of an MI resolves in less than 15 min. C. The type of activity that causes an MI can be identified. D. Angina can occur for longer than 30 min.

A. CORRECT: Angina can be relieved by rest and nitroglycerin.

3. A nurse is caring for a client who asks why her provider prescribed a daily aspirin. Which of the following is an appropriate response by the nurse? A. "Aspirin reduces the formation of blood clots that could cause a heart attack." B. "Aspirin relieves the pain due to myocardial ischemia." C. "Aspirin dissolves clots that are forming in your coronary arteries." D. "Aspirin relieves headaches that are caused by other medications."

A. CORRECT: Aspirin decreases platelet aggregation that can cause a myocardial infarction.

Thallium scan

Assesses for ischemia or necrosis. Radioisotopes cannot reach areas with decreased or absent perfusion, and the areas appear as "cold spots." NURSING ACTIONS: Instruct the client to avoid smoking and consuming caffeinated beverages 4 hr prior to the procedure. These can affect the test.

2. A nurse on a cardiac unit is reviewing the laboratory findings of a client who has a diagnosis of myocardial infarction (MI) and reports that his dyspnea began 2 weeks ago. Which of the following cardiac enzymes would confirm the MI occurred 14 days ago? A. CK‑MB B. Troponin I C. Troponin T D. Myoglobin

C. CORRECT: The Troponin T level will still be evident 10 to 14 days following an MI.

Cardiac catheterization

● A coronary angiogram, also called a cardiac catheterization, is an invasive diagnostic procedure used to evaluate the presence and degree of coronary artery blockage. ● Angiography involves the insertion of a catheter into a femoral (sometimes a brachial) vessel and threading it into the right or left side of the heart. Coronary artery narrowing and occlusions are identified by the injection of contrast media under fluoroscopy. NURSING ACTIONS ● Ensure the client understands the procedure prior to signing informed consent. ● Ensure that the client remains NPO 8 hr prior to procedure. ● Ensure that the client and family understand the procedure. ● Assess for iodine/shellfish allergy (contrast media).

MEDICATIONS: Thrombolytic agents

● Alteplase and reteplase are used to break up blood clots. ● Thrombolytic agents have similar side effects and contraindications as anticoagulants. ● For best results, give within 6 hr of infarction. NURSING CONSIDERATIONS ● Assess for contraindications (active bleeding, peptic ulcer disease, history of stroke, recent trauma). ● Monitor for effects of bleeding (mental status changes, hematuria). ● Monitor bleeding times: PT, aPTT, INR, fibrinogen levels, and CBC. ● Monitor for the same side effects as anticoagulants (thrombocytopenia, anemia, hemorrhage). ● Administer streptokinase slowly to prevent hypotension. CLIENT EDUCATION: Remind the client of the risk for bruising and bleeding while on this medication.

COMPLICATIONS: Dysrhythmias

● An inferior wall MI can lead to an injury to the AV node, resulting in bradycardia and second‑degree AV heart block. ● An anterior wall MI can lead to an injury to the ventricle, resulting in premature ventricular contractions, bundle branch block, or complete heart block. NURSING ACTIONS ● Monitor ECG and vital signs. ● Administer oxygen. ● Administer antidysrhythmic medications. ● Prepare for cardiac pacemaker if needed.

EXPECTED FINDINGS

● Anxiety, feeling of impending doom ● Chest pain: substernal or precordial - Can radiate down the shoulder or arm, or present as jaw pain - Can be described as a crushing or aching pressure ● Nausea ● Dizziness PHYSICAL ASSESSMENT FINDINGS ● Pallor, and cool, clammy skin ● Tachycardia and heart palpitations ● Tachypnea and shortness of breath ● Diaphoresis ● Vomiting ● Decreased level of consciousness

MEDICATIONS: Antiplatelet agents

● Aspirin and clopidogrel prevent platelets from forming together, which can produce arterial clotting. ● Aspirin prevents vasoconstriction. Due to this and antiplatelet effects, it should be administered with nitroglycerin at the onset of chest pain. NURSING CONSIDERATIONS ● Antiplatelet agents can cause GI upset. ● Use cautiously with clients who have a history of GI ulcers. ● Tinnitus (ringing in the ears) can be a sign of aspirin toxicity. CLIENT EDUCATION ● Remind the client of the risk for bruising and bleeding while on this medication. ● Encourage the client to use aspirin tablets with enteric coating and to take with food. ● Tell the client to report ringing in the ears.

CLIENT EDUCATION

● Cardiac rehabilitation should be consulted for a specific exercise program related to the heart. ● Nutritional services, such as a dietitian, can be consulted for diet modification or weight management. ● Instruct the client to monitor and report signs of infection, such as fever, incisional drainage, and redness. ● Teach the client to avoid straining, strenuous exercise, or emotional stress when possible. ● Regarding response to chest pain: follow instructions on use of sublingual nitroglycerin. ● If client is a smoker, encourage smoking cessation. ● Encourage the client to remain active and to exercise regularly.

HEALTH PROMOTION AND DISEASE PREVENTION

● Maintain an exercise routine to remain physically active. Consult with a provider before starting any exercise regimen. ● Have cholesterol level and blood pressure checked regularly. ● Consume a diet low in saturated fats and sodium. Consult with a provider regarding diet restrictions. ● Promote smoking cessation.